Now, with one word we learned today, how can we combine these 8 local histograms,
each of which summarizes the histogram for 16 items assigned to that thread,
into one global histogram?
现在，用我们今天学到的一个词来回答， 我们如何把这8个局部直方图
它们中的每一个都汇总了分配给那个线程的 16个数据项的直方图，
合并到一个全局直方图？